OMEMO trust policy can now be specified. For now there are 2 policies:
- `manual`: each new device fingerprint must be explicitly trusted or not before the
device can be used, and the message sent
- `BTBV` (Blind Trust Before Verification): each new device fingerprint is automically
trusted, until user manually trust or not a device, in which case the behaviour becomes
the same as for `manual` for the entity. When using the Trust UI, user can put the
entity back to blind trust if they wish.
A message is send as feedback to user when a new device is/must be trusted, trying to
explain clearly what's happening to the user.
Devices which have been automically trusted are marked, so user can know which ones may
cause security issue.
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